Device for the automatic balancing of washing and drying machines

ABSTRACT

A device for rebalancing the rotary baskets of washing machines and the like, of the kind in which liquid masses are used for balancing the basket. The rear wall of the basket is elastically deformed (for example, it is a metal disc) and the deformations are transferred to a valve which feeds with liquid a number of peripheral chambers mounted on the basket. As rebalancing is achieved, the deformation of the disc ceases and the valve is closed. Water is spontaneously discharged in the usual suds tub.

[21] Appl. No.: 166,502

[30] Foreign Application Priority Data Aug. 1, 1970 U.s. Cl. 210/144,210/363 1m. c1 B01d 33/40 Field of Search 210/144, 363, 365

I? PK Italy .28196/70 1 UnIted States Patent 1 1111 3,7993% Mazza Mar.26, 1974 [5 DEVICE FOR THE AUTOMATIC 2,224,241 12/1940 Uerdier et al210/144 BALANCING 0F WASHING AND DRYING {28 I 1 eyer MACHINES 3,117,9261/1964 Starr et all 210/144 [75] Inventor: Lamberto Mazza, Pordenone,Italy a [73] Assignee: Industrie A. Zanussi S.p.A., PrimaryExaminer-John Adee Pordenone, Italy Attorney, Agent, or Firm-Holman &Stern [22] Filed: July 27, 1971 [5 7] ABSTRACT A device for rebalancingthe rotary baskets of washing machines and the like, of the kind inwhich liquid masses are used for balancing the basket. The rear wall ofthe basket is elastically deformed (for example,

it is a metal disc) and the deformations are transferred to a valvewhich feeds with liquid a number of peripheral chambers mounted on thebasket.

As rebalancing is achieved, the deformation of the disc ceases and thevalve is closed. Water is spontaneously discharged in the usual sudstub.

5 Claims, 4 Drawing Figures PATENTEDHARZS m4 SHEET 2 (IF v4 DEVICE FORTHE AUTOMATIC BALANCING OF WASHING AND DRYING MACHINES BACKGROUND OF THEINVENTION This invention consists of a device, which is adapted tobalance automatically the rotors of washing, centrifuging machines andthe like.

In washing and drying machines, the rotary mass is never exactlycentered relatively to the axis of rotation.

It sufficesto consider the linen which is loaded into the rotating drumof a washing machine or to vegetables loaded in a centrifuging machinefor removing water. The loads of linen, vegetables and other materialscannot be introduced by an operator in such a way as to achieve asatisfactory static and dynamic balancing of both static and dynamic,which originate a radial force which rotates about the axis of rotation,and a torque lying on a plane passing through the axis of rotation andwhich rotates therewith, respectively.

Said rotary force and torque give rise to oscillations or vibrations,which originate serious problems as to the practicability of embodyingstructures adapted to withstand them.

- Such'problems are generally solved in one of the following manners:

a. By providing a drum, ashaft and bearings and an overall structurewhich are so robust as towithstand, without appreciable deformation (analmost rigid system) to the stresses originated by the rotor unbalance.

Ina'ddition, the machine should be sturdily anchored to the floor toprevent jerks and displacements of the machine.

Lastly, the slab or the floor should have a specially provided, concretebedplate, or a bedplate of another materiaLwhich does not impair thesafetyofthe building in which the machine should operate.

Thismethod, for example, is used for many industrial laundry washers andthe shortcomings are apparent, such as a high first cost of thestructure and all the component parts of the machine,'a high cost forthe installation of. the machine, vibrations and noise transferred tothe spaces adjacent to that wherethe machine is operative. 1

b. Supporting the rotor and the motor, or the whole supporting structuretherefor, with an elastic and dampening system, that is, with springsand shockabsorbers. i

In such a case, the drawback is the cost of the resilient suspension fordampening, and the supporting structure for them.

masses to the mostappropriate positions. Such a system has the defect ofbeing costly and .has' been suggested by prior inventors, such as GeorgeN. Starr and Nor-vin L. Pellerin, in the US. Pat. No. 3,117,926.

OBJECTS AND SUMMARY OF THE INVENTION The object is to suppress theoscillations due to rotor unbalance when the latter is rotated at a highspeed.

The device according to the present invention is of the kind comprisinga rotary basket as mounted in a cantilever fashion on its driving shaftand having peripheral chambers adapted to house a liquid for balancingthe abnormal stresses, and more particularly those due to irregulardistribution of the linen in the interior of the basket which is rotatedat a high speed, said device being characterized in that it comprises aportion of the basket which is elastically deformable under the actionof an unbalance of the basket, and is adapted to actuate, by itsdeformations, mechanical meansto feed said liquid to one or more of saidchambers, with said mechanical means being rotatable integrally with theshaft and the basket attached thereto.

According to a preferred embodiment, the elastically deformable portionof the basket is the back wall of the basket, perpendicular to therotation shaft, or, as an alternative, a portion'of said wall, such as adisc of a deforrnable material which supports the basket.

Each chamber is fed, according to the invention, through an inlet valvefor each peripheral chamber, whose valve body is integral with therotary shaft for the basket, while the stem of the movable head of thevalve is driven by a member (such as a simple strap) affixed to thedeformable wall of the basket with, the outlet port of each chamberbeing formed in the area nearest to the axis of rotation, in directcommunication with the tub which is external of the rotating basket.

The operative and structural features of the device will become clearerby having reference to one of the possible embodiments as shown in theaccompanying drawings, wherein:

BRIEF DESCRIPTION or THE DRAWINGS FIG. 1 shows an axial cross-sectionalview of a laundry washing machine according to the invention, withcentrifuge.

FIG. 2 is a cross-sectional view taken along the line II II of FIG. 1. A

FIG. 3 is a cross-sectional close up view of the feeding valve and thedischarge outlets for an individual balancing chamber, and

FIG. 4 shows a cross-sectional detail view of one of the chambersaffixed to the drum and associated with a rubber cavity which.mates theinner walls of the chamber.

DETAILED DESCRIPTION OF THE INVENTION The device as shown hereinessentially comprises a foraminous rotary basket 1, a fixed external tub2, a front door 4 defined by a hinged door which closes the tub at thefront, and a supporting structure 3.

A The rear wall of the basket I is an elastically deformable metal disc5, mounted in an overhanging manner on a rigid shaft 6, which is rotatedin appropriate bearings 26 and driven by a drive-transfer member such asa sheave or pulley 27. The basket has three or more peripheral chambersor reservoirs, ll, evenly angularly spaced apart along the periphery ofthe basket (FIG. 2).

In the neighborhood of the wall of each reservoir 11, which confrontsthe axis of rotation of the basket, a port 21 (FIG. 3) opens, throughwhich the head portion of a tubular body 10 of an inlet valve is passed,with the inlet valve formed by an outlet mouth 12 being closed by amovable plug or head 20 mounted on a stem 17 which emerges in asealtight manner from the rear base of the body 10 and which, by meansof a return spring 19, tends to keep the inlet valve normally closed.The tubular body 10 is integrally connected to, and in communicationwith, a stiff or rigid radial duct 14 which, in turn, communicates withan axial duct 13 to allow the water under pressure coming from the watermain through a fixed fitting 25 which is sealtight when rotated, to feedthe reservoir 11.

In front of the head of the stem 17 there is a plate 9 which is affixedto the deformable disc 5. The plate has an adjustment screw 15 with itsattendant locking nut 16.

According to an improved embodiment (see FIG. 4) a rubber container 24is inserted in each of the individual reservoirs 11 and is adaptedperfectly to match, with its walls, the inner walls of the reservoir.This approach allows a considerable cost reduction to be achieved, inthat it dispenses with time-consuming operations for a sealtight weldingon the stainless steel of the basket and permits a simpler connection ofthe reservoir to the basket, and of the tubular valve body to thereservoir.

Likewise, the resilient disc 5 can be replaced, for the ends ofbalancing, by an annular rubber disc 23 (FIG. 4) which, by beingdeformed, enables the plate 9 to drive the stem 17 of the inlet valve.

Lastly, it should be noticed that the water of the reservoir 11 can bedirectly dumped into the tub through the hole 21 which is not entirelyclosed by the tubular body of the inlet valve.

During centrifuging, if the irregular distribution of the linen 7produces a torque which deforms the disc 5, the plate 9 and its screw 15press the stem 17 and thus open the inlet valve, so that water entersthe reservoir ll concerned until the incoming water mass produces,during its rotation, a torque which is equal and opposite to theunbalancing torque, so that the system becomes balanced and undesirablevibrations are put down thereby.

In FIG. 2, in which the water held in the reservoirs 11 is indicated at11a, the equilibrium condition is diagrammatically depicted in the mostgeneral case where two reservoirs 11 are subjected to the water feed todifferent degrees, in order to effect balancing.

Once balancing has been achieved, inasmuch as the deformation of thedisc 5 is discontinued, the plate 9 is set back and allows the returnspring 19 to close the valves 12-20.

On completion of centrifuging and during the attendant basket slow down,the water held in the reservoir is permitted freely to flow into themachine tub through the ports 21.

What is claimed is:

l. A device for the automatic balancing of washing and centrifugingmachines of'the type including a horizontal driving shaft, a rotarybasket, said basket having an elastically deformable vertical rear wall,said rear wall being mounted on the driving shaft whereby the basket iscarried in a cantilever manner on the driving shaft, and means withinthe basket defining peripheral chambers for receiving an amount ofliquid for balancing the unbalancing stresses due to an irregulardistribution of the. basket load, improvement comprising valve means forfeeding liquid to at least one of the chambers, means operably mountingthe valve means on the shaft and basket for rotation in unisontherewith, a plate affixed to the deformable rear wall of the basketadjacent the valve means, and a valve actuating member carried by theplate and operated by the deformation of said rear wall for actuatingthe valve means to feed liquid to said at least one chamber.

2. A device for the automatic balancing of washing and centrifugingmachines of the type including a driving shaft, a rotary basket mountedin an overhanging manner on the driving shaft, and means within thebasket defining peripheral chambersfor receiving an amount of liquid forbalancing the unbalancing stresses due to an irregular distribution ofthe basket load, the improvement comprising valve means for feedingliquid to at least one of the chambers, means operably mounting thevalve means on the shaft and basket for rotation in unison therewith,said basket having a portion thereof which is elastically deformableunder the action of an unbalance of the rotary basket, and meansdirectly operated by the deformation of such portion for actuating thevalve means to feed liquid to said at least one chamber, in which thereis a valve means for each chamber, each valve having a hollowed bodyintegral with the driving shaft, said body having an outlet, a head forclosing the outlet, an actuating stem secured to the valve headextending axially of the hollow body, and an operating member affixed tosaid elastically deformable portion operative upon deformation of saidportion to actuate the stem to move the head to open the outlet, anouter tub in which the basket is located and each chamber having anoutlet in directand continuous communication with the outer tub, withthe outlet of each valve extending through the outlet of each chamberinto the interior thereof.

3. The device as claimed in claim 2 in which a duct located externallyof the basket is affixed to the driving shaft and valve body, thedriving shaft having an axial bore for feeding liquid, said axial borebeing in communication with the interior of the duct to allow flow ofthe feeding liquid into the chamber when the head opens thevalve bodyoutlet, and spring means within the valve body normally biasing the headto close the valve body outlet.

4. The device as claimed in claim 2 including a rubber containerinserted in said chamber as snugly mating the means defining thechamber.

5. The device as claimed in claim 2, in which said operating memberincludes a plate affixed to said elastically deformable portion in frontof said actuating'stem secured to the valve head, and a screw carried bysaid plate for actuating said stem.

1. A device for the automatic balancing of washing and centrifugingmachines of the type including a horizontal driving shaft, a rotarybasket, said basket having an elastically deformable vertical rear wall,said rear wall being mounted on the driving shaft whereby the basket iscarried in a cantilever manner on the driving shaft, and means withinthe basket defining peripheral chambers for receiving an amount ofliquid for balancing the unbalancing stresses due to an irregulardistribution of the basket load, improvement comprising valve means forfeeding liquid to at least one of the chambers, means operably mountingthe valve means on the shaft and basket for rotation in unisontherewith, a plate affixed to the deformable rear wall of the basketadjacent the valve means, and a valve actuating member carried by theplate and operated by the deformation of said rear wall for actuatingthe valve means to feed liquid to said at least one chamber.
 2. A devicefor the automatic balancing of washing and centrifuging machines of thetype including a driving shaft, a rotary basket mounted in anoverhanging manner on the driving shaft, and means within the basketdefining peripheral chambers for receiving an amount of liquid forbalancing the unbalancing stresses due to an irregular distribution ofthe basket load, the improvement comprising valve means for feedingliquid to at least one of the chambers, means operably mounting thevalve means on the shaft and basket for rotation in unison therewith,said basket having a portion thereof which is elastically deformableunder the action of an unbalance of the rotary basket, and meansdirectly operatEd by the deformation of such portion for actuating thevalve means to feed liquid to said at least one chamber, in which thereis a valve means for each chamber, each valve having a hollowed bodyintegral with the driving shaft, said body having an outlet, a head forclosing the outlet, an actuating stem secured to the valve headextending axially of the hollow body, and an operating member affixed tosaid elastically deformable portion operative upon deformation of saidportion to actuate the stem to move the head to open the outlet, anouter tub in which the basket is located and each chamber having anoutlet in direct and continuous communication with the outer tub, withthe outlet of each valve extending through the outlet of each chamberinto the interior thereof.
 3. The device as claimed in claim 2 in whicha duct located externally of the basket is affixed to the driving shaftand valve body, the driving shaft having an axial bore for feedingliquid, said axial bore being in communication with the interior of theduct to allow flow of the feeding liquid into the chamber when the headopens the valve body outlet, and spring means within the valve bodynormally biasing the head to close the valve body outlet.
 4. The deviceas claimed in claim 2 including a rubber container inserted in saidchamber as snugly mating the means defining the chamber.
 5. The deviceas claimed in claim 2, in which said operating member includes a plateaffixed to said elastically deformable portion in front of saidactuating stem secured to the valve head, and a screw carried by saidplate for actuating said stem.